Adjustable gearing



Oct. 24, 1950 G. w. MULLER ADJUSTABLE GEARING Filed Oct. 28, 1947 u. s Ru W. m N R YR N! E 0 MM Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE 2,526,964 ADJUSTABLE GEARING Application October 28, 1947, Serial No. 782,667

In France November 12, 1946 2 Claims.

The present invention relates to systems including at least one gear train with an adjustable distance between pinion axes and it is more especially, although not exclusively, concerned with systems of this kind in which the said gear train belongs to a gear pump.

The chief object of my invention is to provide a system of this kind which is better adapted to meet the requirements of practice than those used for the same purpose up to this time.

Preferred embodiments of my invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example and in which:

Fig. 1 shows, in axial section, a gear pump made according to my invention.

Fig. 2 shows a modification of the pump shown by Fig. 1.

In the following description, it will be supposed that the invention is applied to a pump intended to steady the flow of a fluid such as viscose for feeding the spinning nozzles of an artificial fiber spinning machine.

Concerning the construction of the pump, with the exception of the means for supporting the pinions thereof, it may be arranged of any suitable kind, for instance such as shown by the drawing. This pump is constituted by a plurality of juxtaposed plates. In one of these plates I,

located approximately in the middle part of the pump and including two recesses, are housed the two pinions 2 and 3 which constitute the gear train of the pump. One of them, the driving pinion, for instance pinion 2, is driven from the outside, while the other one, the driven pinion, in this example pinion 3, receives its movement through the driving pinion. I provide, in said plate I, on either side of the place where the two pinions? and 3 are in mesh with each other, the suction and delivery chambers of the pump, not shown by the drawings, these chambers communicating with the suction and delivery conduits.

Concerning plates 4 and 5, immediately adjacent to plate I, they constitute, in the embodiment of Fig. 1, distance plates interposed between, on the one hand, plate I and, on the other hand, closure plates 5 and l disposed on either side of said plate. The whole of these plates, connected together by bolts 8, forms the casing of the pump which contains gear train 2--3.

Pinions 2 and 3 are carried by spindles 9 and Ill which are fixed in at least one of the closure plates. The positioning of these spindles or shafts determines the distance between pinions ions are in mesh, therefore, among other things,

upon the distance between the axes of rotation of the two pinions.

For practical purposes, more or less important leak is unavoidable.

.In the case of pumps running at a relatively high speed, a very accurate machining of the gears, plates, shafts and shaft housings suffices to ensure a practical flow rate very close to the theoretical volumetric rate.

On the contrary, in the case of pumps running very slowly as it is the case for the pumps that steady the flow rate of viscose and feed the spinning nozzles of artificial fiber spinning machines, it is very difficult to obtain, in mass production, systems which, without adjustment after machining, give a satisfactory efliciency. Therefore it will be necessary to provide adjustment means, in particular for the distance between pinion axes, for rectifying the differences coming from manufacturing tolerances, to give the pump a satisfactory efficiency.

Said adjustment is, preferably, performed at the manufacture works to be subsequently main tained, without the user of the pump being able, even if he takes the pump to pieces for cleaning purposes, to destroy the adjustment obtained when assembling the pump elements.

For this purpose, and according to the main feature of my invention, the spindle of at least one of the pinions 2 and 3, preferably the driven pinion 3, includes at least two portions H1 and Hi the axes of which, instead of coinciding, are eccentric with respect to each other, portion 18 acting as a journal for pinion 3, while portion lll is fixed in closure plate 6, after it has been angularly adjusted therein, this adjustment, due to the eccentricity E (averaging some tenths of a millimeter) provided between portions Hi and I0 having for its effect to adjust the distance between the axes of pinions 2 and 3 and therefore the leak that may take place in the pump.

Furthermore I provide locking means to fix the position of shaft it! with respect to closure'plate 6, in which this shaft is housed, once the adjustment of the distance between axes has been obtained.

For instance, in order to lock shaft ill with respect to plate 6, said shaft is provided with a threaded end IE on which is screwed a nut ll,

which, once tightened, prevents, in cooperation with a suitable washer 12 (for instance one of the kind known as Grower washers) any unlocking of shaft I0. I may provide, at the other end of this shaft, a slot I3 in which a screw-driver can be engaged to rotate said shaft, before lookin thereof, in order to adjust the distance between pinion axes of the gear train.

Another embodiment of the means for locking shaft after adjustment of the distance between pinion axes is illustrated by Fig. 2, which shows only a portion of a pump in which closure plate 6 is directly adjacent to plate I and there is no plate 5.

According to this Fig. 2, the portion Hi of shaft [U that is housed in closure plate 8 is made expansible, being constituted by a hollow cylinder having a slit wall and the inner surface of which is conical, and an expansion cone i4 cooperates with said conical surface, said cone being adapted to be driven in by a screw [5, to expand the portion I0 of shaft l9 and lock this shaft inside closure plate 6, after adjustment of the distance between the pinion axes of gear train 2-3, by fixation of the angular position of shaft [0 with respect to plate 6.

It should be noted here that, during the adjustment of the distance between axes by fixation of the angular position of spindle or shaft ID, plate I describes an oscillating movement about the axis of driving pinion 2, with respect to the other plates of the pump.

Consequently, the holes in said plate through which pass assembly screws 8 must have, with respect to said screws, a play equal to or greater than the amplitude of this movement. It is also necessary to provide a sufiicient play in the bore 4a of plate 4 that accommodates the free end of shaft ID.

The means for rotating the driving pinion 2 of a gear pump made according to my invention act on shaft 9 on which pinion 2 is directly fixed.

However, according to another feature of my invention, I fix shaft 9 in closure plate 6, for instance with a force fit, thus avoiding any leakage through closure plate 6, at the place where the end of spindle S is fixed in said plate and I journal on spindle 9 a sleeve 2! on which pinion 2 is fixed. In order to drive sleeve 2'; from driving shaft 28, I provide a pin 29 extending through sleeve 2'! and which engages in a slot 36 provided in the end of said shaft 28.

This last mentioned shaft is housed in an axial extension 3i of closure plate I, a collar 32 being provided on shaft 28 to fit between a shoulder 33 of closure plate I and the outer face of distance plate 4, thus preventing any axial displacement of shaft 28.

I fix on the outer end of shaft 28 a driving pinion 34, for instance, by means of a pressure screw 35 which is applied, preferably, upon a fiat portion 36 of said shaft 28.

In order to ensure lubrication of driving shaft 28 and its collar 32, a portion 31 of the delivery conduit of the pump extends along shaft 28 and its collar 32 which are thus constantly immersed in the fluid that flows through the pump.

In order to ensure fiuidtightness at the outer end of projection St, I provide a hydraulic joint 38 kept in position by nut 39.

It is clear that the distance between the axes are in mesh with each other, so as thus to obtain the minimum leakage and the best possible flow rate.

By adjusting the distance between axes and thus modifying the play, it is also possible to vary the flow rate of the pump in order to obtain a more accurate gauging of the volumetric fiow rate thereof.

Adjustment of the distance between axes, according to my invention, might also be utilized to take up the play that might be produced by wear and tear after a long time of service.

Still another advantage of my invention consists in this: In high precision gear pumps such as viscose pumps, the pinions must have an extremely small clearance in the recesses of the plate in which they are housed. It follows that, in known pumps, account being taken of the possible tolerances of manufacture for the distance between axes, the pinions, which are pushed away from each other by the pressure of the fluid forced by the pump, bear, most often, not through their bores on their spindles, but through the heads of their teeth on the bore of the recesses provided in said plate. This constitutes a serious drawback because the gear teeth, then acting as milling tools, quickly wear off these recesses so that the pumps get out of action. With above mentioned means for adjusting the distance between axes, this drawback of known pumps is wholly eliminated.

This is due to the fact that, owing to this adjustment, which keeps the bores of the pinions in contact with the generatrices of their respective spindles that are closest to each other, the pinions, in a pump made according to my invention, are applied by the fluid pressure against their respective spindles.

The gear train with an adjustable distance between axes might include several driven pinions, each provided with an adjustment device according to my invention.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and eificient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

l. A device which comprises, in combination, a plate, two intermeshing pinions mounted in said plate, a closure plate on either side of said first mentioned plate, a crank piece including two portions of revolution having their axes eccentric with respect to each other, one of said portions being housed with angular adjustment about its axis in one of said closure plates at right angles Jereto and the other acting as a journal for one of said pinions, means for locking the first mentioned portion in the closure plate that houses it in any desired angular position about its axis in said closure plate, said plates are provided with registering holes, respectively further including bolts for assembling said plates extending through said holes, the holes provided in said central plate having a play with respect to said bolts to permit displacements of said central plate with respect to said closure plates when said first mentioned portion is rotated in its housing in the corresponding closure plate.

2. A device which comprises, in combination, a plate, two intermeshing pinions mounted in said 5 plate, a closure plate on either side of said first mentioned plate, a crank piece including two portions of revolution having their axes eccentric with respect to each other, one of said portions being housed with angular adjustment about its axis in one of said closure plates at right angles thereto and the other acting as a journal for one of said pinions, means for locking the first mentioned portion in the closure plate that houses it in any desired angular position about its axis in said closure plate, a spindle coaxial with the second pinion, said spindle being fixed in one of said closure plates, a sleeve journalled on said spindle operatively connected with said second pinion to rotate together therewith, and a shaft for rotat- 15 ing said sleeve.

GEsA WALTER MULLER.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,171,347 Morse Feb. 8, 1916 1,602,740 Bechler Oct. 12, 1926 1,712,956 Gustafson May 14, 1929 FOREIGN PATENTS Number Country Date 421,373 Germany Nov. 10, 1925 172,159 Switzerland Sept. 30, 1934 

